Oxidative Iodination of Arenes with Manganese(IV) Oxide or Potassium Permanganate as the Oxidants

Novel and easy laboratory methods (novel Procedures 1—4) are presented for the oxidative mono- and diiodination of both activated and deactivated arenes, which gave the pure iodinated products in 62—89% yields. The reactions were carried out in the anhydrous, strongly acidic system, I2/activated MnO2/AcOH/Ac2O/concd H2SO4, firstly at r.t. for 2 h, then at 45—55 °C for 2—9 h. The resulting mixtures were poured into excess aq Na2SO3 solution buffered with (NH4)2CO3 to neutralize H2SO4. The following workups are given. Similarly, on carrying out the iodination reactions (at 35 °C, for one hour) in the anhydrous, strongly acidic system, I2/KMnO4/AcOH/Ac2O/concd H2SO4, it was possible to mono- or diiodinate several deactivated arenes in 73—87% yields (improved Procedures 5 and 6).